Main > Monitor/Video Forum
Pentranic 1132 (CH-288) No Picture & Chirping - [FIXED!!!!!!]
grantspain:
quite a common fault on pentanics,also worth noting that the high voltage cap on the collector can be blown
gokun:
Ok, well I verified everything as far as the HOT, and I had a BU2520DF in there originally and in addition to a few other types I got(just in case) at the time I got one of these too which is supposed to be legit as far as I can tell(but still ebay so you never know)...at any rate, I'm happy to report I'm getting at least 1 of the proper replacement part. :) Will let you all know how fast it explodes once I get it and install it ;p
gokun:
Hey guys....unfortunately the new HOT did not fix the problem....while the chirping DID become noticeably less frequent(e.g. it's chirps slower now than before) it is still, alas, not working...
None of the other components I checked seemed bad(although obviously I do not know how to test the more complicated parts properly-but all the basic stuff like capacitors check out)...
if it makes a difference I was able to pinpoint where the sound is coming from...I think...it seems now to be coming directly from the anode suction cup(or very very near that area)...does that make sense to anyone or are my ears playing tricks on me?
At any rate, I'm open to ideas...thanks!
qrz:
hv is likely pulsing in time with the smps. there is still something amiss in the circuitry - next component that can load the smps is the vert output ic. disconnect b+ to the chip and BRIEFLY ( i.e. < 5 seconds) pwr it up.
if the supply comes up to voltage ( no ticks) then replace the ic.
qrz
gokun:
ok,ok,ok...I know it's 2am but this whole affair has me really depressed so I feel obligated to keep at it....anyhoo, I need some clarification on something...I'm currently working under the assumption(based on things I've read,etc) that the FET, vert ic, etc. is on the small board in the back(attached to the back of the yoke? still not 100% on all the terminology)...is this correct?
I ask because after many, many hours of reading and researching, I found someone with a similar monitor(pentranic 33") with the exact same problem and the supposed solution was that he replaced the FET, IC and capacitors on "a small circuit board in the back." I'm assuming this is the one I mention as it has an IC, caps obviously, and what looks like the right type to be the FET....but again, I am new to monitors and the schematics are much more complicated and much harder for me to read than the PCB schematics I usually deal with...so I guess I'm looking for verification here(or to tell me I'm wrong before I muck something up).
Also worth mentioning is that the new HOT has not blown as of yet and I believe I misread the old one and that it is indeed still good as well(once I got the 2 new ones in I was able to do much better testing as I had a basis for comparison, which finally made it all make sense to me in regards to the HOT...I'm a designer by profession so I suppose I'm just a visual person by nature)...
anyways, back on the subject at hand, I would like to once more extend my thanks to everyone for all the help.
I'm still hopeful that maybe we can get this damn thing running again. :)