By David Coe, founder and bench technician
Reflow vs rework: why one of them is not a repair
Search any device repair phrase and a hundred voices will tell you to "just reflow it". A reflow (heating a board or a chip until the existing solder re-melts) is the most famous shortcut in electronics and the most misunderstood. It is worth being precise about what it does, what it does not do, and why a board that "worked after a reflow" is a story with a second chapter.
The two, defined
- Reflow: heating a joint, a region or a whole board so existing solder melts and re-forms a connection. No component is replaced, nothing is diagnosed, nothing is verified except "it switched on".
- Rework: removing the failed component or connector, preparing the board, fitting a replacement (or a rebonded chip, in BGA work) and testing the result. The fault is found, then fixed.
Why reflows "work", and then stop
Heat does wonderful, temporary things. It can re-wet a cracked joint, soften corrosion bridges, and reset a thermal-sensitive fault long enough for a machine to boot and be handed over. What it cannot do is fix the reason the joint cracked: shorted components that cook nearby solder, thermal cycling that will cycle again, or a chip whose internals are already dead. The machine boots, the customer pays, and it comes back weeks later. Usually worse, because now the failure is a surprise and the board has been heat-stressed on top of being broken.
The heat-gun problem
Amateur reflows are worse than the theory suggests. Without preheaters, the board flexes and warps; without proper temperature control, neighbouring chips, plastics and solder-masked traces take damage; with hot air in the wrong place, corrosion spreads under components. What arrives from a "reflowed" machine is frequently previous-repair damage on top of the original fault. Two jobs instead of one.
What proper work looks like instead
- Diagnose to the component: the fault named before any heat arrives.
- Rework, not warm: the component replaced or the BGA removed, reballed and refitted with temperature-controlled equipment.
- Test under load: the repaired machine stressed like the customer will use it, not just switched on.
- Warrant the result: 12 months on the repair, at this bench, because that is what genuinely repaired work can carry.
The £120 + VAT fixed laptop logic board repair exists because rework is the actual product, and the reason a bench like this can offer a year of warranty where a reflow merchant offers a handshake.
Reflow and rework questions
Is a reflow ever a legitimate repair?
As a last-resort diagnostic trick, rarely; as a repair, no. Heat can re-wet a joint just long enough to boot, but it cannot fix the reason the joint failed, which is why the machine comes back worse.
A shop offered to reflow my board. Should I take it?
Understand what you are buying: heat stress on the board, damage risk to neighbouring components, no fault actually found, and no warranty worth having. Rework replaces what failed; reflows delay it.
What do you do instead?
Diagnose to the component, replace or reball it with temperature-controlled equipment, test under load, and carry a 12-month warranty on the repair. That is what the fixed £120 + VAT board repair buys.
The books are full. Join the list
Our bench is at capacity, so we are not taking new jobs right this moment. Open a trade account and we will email you the moment we are booking again. No commitment. Questions? Email jobs@soldersector.com.
