Shout out to all techs:Rebuild or Replace

[ReeceyBurger123]

Re: Shout out to all techs:Rebuild or Replace

Rebuild, theres no job satisfaction in just replacing a board , any one can do that, if a IGBT or transistor is short always replace the driver IC, a transistor can be tested , an IC cant.

I have found that when a Tran fails and takes the Ic out it has very low ohms reading across all the pins I have also had ones that go completely S/C or blow up on some Vestel boards.

[tom66]

Re: Shout out to all techs:Rebuild or Replace

I have found that when a Tran fails and takes the Ic out it has very low ohms reading across all the pins I have also had ones that go completely S/C or blow up on some Vestel boards.

I've had one fail leaky that passed tests on the meter but when tested on a scope the output sat at about 4V DC with no switching. That took out two IGBTs before I realised the problem. On a Panasonic SN board. Awkward thing is 4VDC is enough to partially switch on the IGBT so it killed both high and low parts as short-circuit current limiting didn't kick in on the PSU.

I pretty much always replace them now: always replace them on a power supply and 50% of the time swap them on a sustain board. The fault energy is much less on a sustain board (shorted mains can dump 300-400A into an SMD device; a shorted load on the PSU is probably 1/10th that for much less time) so they tend to survive more.

[ReeceyBurger123]

Re: Shout out to all techs:Rebuild or Replace

Thats true Tom remember that thread I had about that SSI400 14A01 invteter ? Controller tested fine on meter but OS proved that it was bad and was causing the fets to blow.

[keeney123]

Re: Shout out to all techs:Rebuild or Replace

I think I will chime in. You could always replace the board and take the bad one and repair it if you had a test fixture for board repair. That way you get your customer up and running fast and when you are waiting for another customer you are repairing boards and building up your repair inventory. This would require a lot of knowledge of how the different systems work. Of course the manufacturers just want to sell another TV so they do not have a lot of interest in you repairing TV's.