An ABB robot stops, and the fault log points at a controller or a drive module. You need one part, you need it right, and you have no way to check the box that arrives. Most suppliers will tell you the unit was tested. The useful question is what that testing actually covered, and what you can verify yourself when the unit lands on your bench.
This guide covers what a real ABB parts testing process looks like, how to confirm a part number before you order, what new, refurbished and exchange units mean for your robot, and when repairing a module beats replacing the whole assembly. If you want the selection criteria first, that is covered separately in How to Choose a Reliable ABB Robot Parts Supplier.
If you have a specific part in front of you, send the robot model, the serial number and the article number read off the label of the failed unit. That is enough to start, and it tells us which variant applies before anyone quotes a price.
What "tested before shipment" should actually mean
The phrase covers everything from a visual inspection to a full functional test, and suppliers use it for both. Here is what each level of testing actually establishes.
| Level | What was done | What it proves | What it does not prove |
|---|---|---|---|
| Visual and dimensional | Board inspected for damage, corrosion, lifted pads, connector pins | The unit is physically intact and not water or burn damaged | That it works at all |
| Power-up and self-test | Unit powered, controller or test rig connected, error codes read | The unit boots, passes its internal self-test, reports no fault | That it survives load, or that it is the right version |
| Functional test | Electrical response, signalling handshake, and where applicable mechanical movement exercised | The unit performs its function under unloaded conditions | That it holds up under sustained load |
| Load and ageing test | Powered under representative load over time, thermal behaviour and output monitored | The unit does not fail under duty, and no component is drifting out of tolerance | That the part number matches your robot |
| Compatibility verification | Configuration, firmware revision and serial range checked against the target robot or controller generation | The unit will be recognised by the controller | That your downstream program is unaffected |
Two things this table makes clear. A unit that passed the first three levels can still be the wrong part. And a supplier who says "fully tested" without telling you which levels they ran has told you nothing verifiable.
There is one more check that happens before any of this, and it costs the supplier nothing: reading the article number off the physical label of the failed unit. A controller that is one revision behind does not fit a robot that expects the newer one, regardless of how well it works on the test bench.
What you can verify yourself on arrival is narrower than a test certificate, but it is not nothing. Four checks take a few minutes and catch the failures that stop a cell.
Power it up on the bench before it goes into the cabinet. A unit that will not boot, or boots and reports an internal fault, tells you immediately that something was wrong with it before it reached you. This is worth doing even for a unit you believe was tested, because a self-test that was not repeated after transit damage is not a self-test.
Read the reported identity. Most ABB controllers and boards report their own article number and revision through the controller or a diagnostic tool. Compare it against what was ordered, character by character, including the suffix. This is the check that catches a wrong-revision delivery, and it takes about a minute.
Confirm the fault code is not a stored one. A unit that was reset after a repair may still report the original fault from its memory. Ask the supplier whether the fault log was cleared before release. A unit arriving with the original fault still in the log tells you the fault was never actually resolved, and you cannot tell that from the outside.
Match the connector and the labelling. Look at the connector type, the keying, and the label against the unit you removed. A unit for a different cabinet generation sometimes fits physically and still fails to communicate. This is where the cheap mismatch shows up.
None of these four checks proves the unit passed a load test, and they are not meant to. They confirm the unit is the right one, that it works, and that the fault you are chasing is the fault that was fixed. Anything beyond that is what the supplier's test documentation is for, and the question to ask is which levels were run.
How to check that the part number matches your robot before you order
ABB article numbers look interchangeable until you notice the suffix. The same base number can carry different revisions, and the revision decides what the unit is compatible with.
Four things to match, in this order.
The base number. Read it off the label of the unit that failed, not from memory or from a previous order. If the label is unreadable, the controller system information or the robot's own configuration records will carry it.
The revision suffix. On a DSQC639 main computer, for example, 3HAC041443-001 and 3HAC041443-003 are different units. ABB's own product pages list both, and the variants are not drop-in replacements for each other. This is the single most common source of a part that arrives and will not be recognised.
The controller generation. The same board number appears across controller families with different interfaces. DSQC-662 and DSQC-663 power distribution units, for example, are not the same unit even though the family pattern looks alike. Confirm against the controller's own system information rather than the board's appearance.
The robot's axis and motion group. For drive units and axis computers, the unit has to suit the axis it sits on, which means the robot model and the specific variant. A drive unit for axes 5 and 6 of one robot is not a drive unit for axis 1 of another.
The variants are easy to get wrong because the family pattern looks alike. A DSQC639 main computer and the DSQC639 main computer with a different revision share a base number and differ in suffix. A DSQC662 power distribution unit and a DSQC661 power supply are different assemblies serving different parts of the same cabinet. The DSQC663 main drive unit and the DSQC431 main drive unit are not interchangeable either.
Ask the supplier for the article number in writing before you order, and ask which of those four it was matched against. A supplier who answers "it should fit" has not done the match.
What to ask for when a supplier quotes you an ABB controller
Quotes arrive as a number and a part number. The number is the easy part. These are the questions that determine whether the quote is usable.
- Is the quoted article number the one I need, or the one we happen to have? These are different questions, and the honest answer is sometimes the second one.
- What is the condition? New original, refurbished, or exchange unit. Each carries different risk.
- What testing did this unit pass, by which levels? Use the table above. If the answer names only a power-up test, that is what you are buying.
- What is the revision, and how was it matched to my controller? Ask for the revision explicitly.
- What is the warranty on this unit, and does it differ between new and refurbished? See the section below, because the answer does differ.
- What happens if it fails? Whether the unit can be returned or exchanged, and on what terms.
If a supplier answers all six quickly and specifically, you are dealing with someone who has a process. If the answers come back vague, the ambiguity will not surface at delivery. It will surface on your bench, with the line stopped and a part that does not fit.
New, refurbished and exchange units: what the difference means for your robot
Three conditions, and the difference between them is not cosmetic. It determines what happens when something is still wrong after installation.
New original. An unused unit with its original ABB documentation. It carries the full parts warranty and the lowest risk of a mismatch, because the part number on the box is the part number ABB built. Where the failure was caused by something external and you have corrected it, this is the right choice.
Refurbished. A unit that has been repaired and brought back to function, then tested. It carries the repair warranty rather than the parts warranty, which is a different thing and a different length. Refurbished is a sound choice for a mechanical or power section fault on a unit where the electronics were never the problem, and an expensive choice when the control electronics are what failed.
Exchange unit. A working unit taken from another machine, tested and released. It is a real part and it will work, but its history is unknown to you and its remaining life is not what a new unit's would be. Exchange makes sense when the cost of downtime dominates the cost of the part, and the unit is going into a machine where a known-good spare is worth more than a longer expected life.
What none of these should be described as is a grade. There is no A, B or C in ABB's own vocabulary for a refurbished part, and any supplier labelling a unit with a letter grade is using a scale the manufacturer does not recognise. Ask instead for the condition, the tests passed, and the warranty that applies to that condition.
The full detail on how we certify a refurbished part, and what a core return involves, is in Refurbished Parts.
What our testing and repair service covers
We are based in Songjiang District, Shanghai, with our own warehouse and stock of ABB modules, and we work with customers whose engineers are on site. Our role is to read the fault remotely, confirm the part number, and supply the unit that fits.
On the testing side, a unit leaving our workshop has been through power-up and self-test, functional verification of its electrical and signal response, and load or ageing testing under representative duty. The specific levels are stated with the quote rather than left to the phrase "fully tested". Where the unit is a controller or a board, configuration and firmware revision are checked against the target robot before it is packed.
On the repair side, we take controllers, drives, power modules, axis computers and I/O boards for board-level diagnosis and repair, where that is the sensible route rather than a full assembly replacement. In practice that covers main computers such as the DSQC639 and the DSQC1018 IRC5 main computer, axis computers such as the DSQC668 and the DSQC601, drive units such as the DSQC663 and the DSQC664 additional drive unit, power sections such as the DSQC661 and the DSQC662, and bus and I/O boards such as the DSQC667 Profibus board and the DSQC652 I/O unit. What we will not do is repair something that should be replaced: a unit with a failed power section or a damaged connector shell is not a repair candidate, and we will say so before you pay for the assessment.
On the commercial side, parts carry 12 months warranty with optional extended cover on request. Repaired units are graded: most carry 12 months, and discontinued series carry 3 to 6 months, confirmed per unit at the quote stage. For a repair, extended cover is priced at the repair cost. Diagnostics and testing are free, and we confirm with you before any repair work begins.
How to repair a module instead of replacing the whole assembly
A drive module and a power distribution unit are assemblies. The question is whether the failure is in the part that failed, or in something cheaper inside it.
Start from the symptom, not the module. A drive that will not power up at all points at the power section, the input supply or the connector. A drive that powers up and reports a motor current error points at the motor, the cable or the tuning. A board that boots and then drops off the bus points at the communication side. The fault log narrows this faster than the module's price tag does.
Ask what the failure mode rules out. Corrosion and burn damage on a power section usually means replacement. A cracked solder joint, a failed filter capacitor, a worn relay or a connector with degraded contacts are all repairable, and each of those is a small part of a much larger assembly.
Weigh the downtime against the price difference. A repair means pulling the unit, shipping it, the bench time, and the risk that the second fault is discovered after the first one is fixed. That time is the real cost of a repair, and on a cell where every hour is a lost shift, it can exceed the price of a new assembly. On a spare unit held in your own warehouse, a repair is often the cheaper option precisely because the machine is already stopped.
Decide whether you need the unit back fast. If the line is down and you cannot wait for a bench cycle, a new or exchange unit is the direct route. If you can run the cell on a spare while the failed unit is on the bench, a repair is worth the assessment.
The service side of this is covered in more detail in Robot Parts Repair Service.
What to send us for a quote
Six items, and the first two are enough to start a conversation.
- Robot model and serial number. These identify the mechanical unit and the controller generation, which is what decides the variant.
- The article number read from the label of the failed unit. This is the single most useful item on the list, because it removes the guessing.
- Controller model and software or RobotWare version.
- The complete alarm text and the event log, not just the last line.
- What has already been changed or replaced before the fault appeared.
- What the robot does now: does it power on, does it jog, does it run a program.
Send the serial number and the article number and we will confirm which unit your robot takes before anything is quoted. If the fault turns out not to be a part at all, we will tell you that instead of selling you something that will not fix it.
Request a Quote
FAQ
How do I know a part has actually been tested?
Ask which levels were run: power-up and self-test, functional test, load and ageing test, and compatibility verification against your controller generation. A unit that passed only a power-up check is a unit that boots. A supplier who names the levels is telling you what you are buying, and one who does not is telling you nothing verifiable.
What is the warranty on new and refurbished parts?
Parts carry 12 months warranty with optional extended cover on request. Repaired units carry 12 months for most items, and discontinued series carry 3 to 6 months, confirmed per unit at the quote stage. Extended cover on a repair is priced at the repair cost.
Should I buy a new unit or a refurbished one?
A refurbished unit makes sense when the failure was mechanical or in the power section and the electronics were never the problem. A new original is the better choice when the control electronics are what failed, or when you want the lowest risk of a revision mismatch. An exchange unit is worth considering when the cost of downtime outweighs the difference in expected life.
Can you repair an ABB controller instead of replacing it?
Yes, we take controllers, drives, power modules, axis computers and I/O boards for board-level diagnosis and repair. We will also tell you when a unit is not worth repairing, usually when the power section or the connector shell is damaged, rather than take the assessment fee and hand it back.
Do you have stock, and how fast can you ship?
We hold ABB modules in our own warehouse in Shanghai, and stock is confirmed against your part number before we quote. Shipping arrangements and timing are confirmed with the quotation rather than promised on a product page, because the answer depends on the part and the destination.
What information do I need to send for a quote?
The robot serial number and the article number read off the label of the failed unit are enough to start. The controller model, RobotWare version and event log narrow it down faster.
Can I ask a technical question without buying a part?
Yes, and a good share of what we receive is exactly that. Send the robot model, the serial number and the alarm history and we will tell you what the fault points at. If the root cause is something your own engineers can fix, we will say so directly.
References
- ABB, Operating manual - Troubleshooting IRC5, document 3HAC020738, for how ABB defines the consequences and causes behind each alarm family.
- ABB, IRC5 controller product documentation, for the controller generations and module designations referenced in this article.
- SongWei Robotics service terms: parts warranty 12 months with optional extended cover, repair cover graded per unit as described above, diagnostics free, 24 hour quote response.
This is an independent technical resource. ABB brand and product names are trademarks of their respective owner. Work inside a controller cabinet must be carried out by qualified personnel with the power disconnected, locked out and the DC link discharged.
