Electronics Forum / Repair / July 2004

I believe that I am having a problem with my convergence STK on my
Pioneer SD-5073 rear projection TV. The problem started a few months
back and would appear more frequently as time went on. Now it is
constant, appearing the entire time the TV is turned on. Here is the

After several months with no problem, this monitor now won't hold
sharp focus.  Adjustment of the focus on the LOPT restores everything
to pin sharp focus, but after a few hours or days the focus has
drifted off again.  Is there any cleaning or remedial action that can

Please send a schematic for the  Acer CD-RW 1208A (12x8x32)
Thanks a million

About a year ago I posted some problems I was having getting my
Pioneer VSX-9700S receiver to work reliably.  I finally fixed it by
using a set of outputs from a junk receiver.  Well, recently I got
curious and cracked open one of the transistors that was in the

Looking for a part number or the horizontal output transistor(Q500).
the set was made by NAP, chassis # is PTV375A001  
The module that its located on is ooem117a001.

Does anyone have a schematic for an hp 90 pavillion, thx

My Alpine receiver won't  hold a signal in FM mode.  If I rap on the FM rf
section it will somtimes come back, play for a few minutes then completely
blank out to a low static. When fm works, it sound excellent.  Everything
else including AM and Cassette works excellent.

I have an Orion TV, model #TV1934. Can't find the chassis number. Set
blows the fuse when plugged in. Found 2 bad diodes in power supply,
replaced them, plugged set back in, and BAM, blown fuse and same 2
diodes toast. I checked the HOT, and power regulator, both are fine. I

I have an old but good Ungar pencil type soldering iron. It had a red
handle with a cork guard next to the heating element. The heating
element has a screw in on one end that goes into the handle then a
ceramic heating element then the end in which the tip screws into. The

Chassis is TAC9868.  The manuals I have are some paper and some
electronic.  Any help would be appreciated!
Alex

Hi,
Keep in mind, our shop is Samsung authorized service and have access
to their stuff.
Really need to ID this chassis to code model so we can get schematic

So I had a defective Damper-Diode-Horizontal-Output-transistor ...
... replaced it and a blown fuse and the dead TV
came on ... it didn't before even with a new fuse.  ;-)
The picture then looked fine except it used to shrink and

The monitor in question is a 5 year old CRT one. On switching on the
monitor, a vertically reduced image near the top of the monitor is all
that can be seen. On giving a blow with the fist or slapping the top
or the sides of the monitor, I get a normal image again. What could be

I recently picked up an Eberline model PAC-ISAGA Alpha Counter radiation
meter and I need to know what to set the high voltage to.
This unit has a scintillation probe to measure alpha particles. This probe
is different from the  Geiger/Meuller probe for gamma measurements.

Two problems with this tape deck and would appreciate any and all
suggestions.
I replaced the capstan drive belt (exact replacement) and the play
speed now is a little  too fast on both speeds 7 1/2ips and 3 3/4 ips.