popescus
Newbie level 2
(pdf)alps uhp061104
Similar to mrzilza's post reply above I found on the invertor board HIU-319C all fuses F2, F3, F4 and F4 broken and transistors Q5 and/or Q6 shorted emitter to collector. This board drives 4 lamps but it hosts 8 ferrite trafos, with every second trafo connected in parallel to the previous one. Each trafo pair is driven by a pair of two FMMT619 transistors. Moreover, it seems that all these switchers are somehow syncronised by means of secondary windings in the transformes.
I guess that if Q5, Q6 gone short-circuit then the oscillation of all other transistor pairs where stopped and this is the reason why all fuses blow up.
Has somebody a diagram for this invertor board? Or maybe had the same problem? I would proceed simple by replacing Q5/Q6 and the fuses ... but prior experince may help to avoid further pitfalls.
Similar to mrzilza's post reply above I found on the invertor board HIU-319C all fuses F2, F3, F4 and F4 broken and transistors Q5 and/or Q6 shorted emitter to collector. This board drives 4 lamps but it hosts 8 ferrite trafos, with every second trafo connected in parallel to the previous one. Each trafo pair is driven by a pair of two FMMT619 transistors. Moreover, it seems that all these switchers are somehow syncronised by means of secondary windings in the transformes.
I guess that if Q5, Q6 gone short-circuit then the oscillation of all other transistor pairs where stopped and this is the reason why all fuses blow up.
Has somebody a diagram for this invertor board? Or maybe had the same problem? I would proceed simple by replacing Q5/Q6 and the fuses ... but prior experince may help to avoid further pitfalls.