Pioneer PDP-502MXE Dead set.

[pan]

Hi all,
Has anyone had this fault?
The set is dead, green LED flashes at times.
Found R108 2.2 ohm 7w on the p/s is o/c, also Q201 2SK2847 is s/c.
I’ve not replaced them yet, done some further cold checks but cannot find any other probs checked for d/js none found.
I just wondered what caused the transistor to fail.
Anyone had the same or similar fault your help will be very much appreciated.
Thanks
Pan 

[Restorer79]

Hi Pan: I can't seem to find R108 on the Circuit diagram.


Andy

[jordan]

PDP502MX

[Restorer79]

Hi Jordan: Downloaded the manual, just in case it was any different to mine. Still can't seem to find R108 though.



Andy

[pan]

Hi Guys,
Sorry my eyesight is not what it used to be, R168 2.2 ohm 7w.
Thanks
Pan

[Restorer79]

Hi Pan: No worries mate, dealing with this sort of stuff day in / out is bound to give you bad eyes.
I'd replace C202 rather than check it, have you checked all the diodes around Q201 ?
Did the fuse blow ?, looking at the Diagnostic chart with Q201 blown Q202 may also be blown & R133 / 34 may also be blown. Chart shows that these components can be blown by a fault on the RCC control (A) assembly or the OTL control (A) assembly.

Good luck, looks like a horrible bit of kit to work on.


Andy

[pan]

Hi Guys,

Yes I’ve checked most of those components out no other faulty part found.
I was told that the TV went intermitted prior to going dead as far as the power supply starting up.
I will go ahead and replace the R168 & Q201 fingers crossed I let you know how it goes.
Thanks
Pan

[pan]

Hi Guys,

No luck the mosfet & Resistor blow on switch on.
Set now returned as could not source a P/S.
Thanks anyway.
Pan

[Restorer79]

Hi Pan: Sorry to hear that mate, that's the trouble with modern stuff it seems to have a mind of it's own & does'nt give in to logical diagnosis.




Andy