disco monitor ver. collasped

voltages on the part????

did you tap on the chassis to see maybe a bad connection..

did you do anything before you ask the question to the chassis?

Post the voltages and someone who is familiar with the standard

voltages would know if they were right or wrong!!

No voltage is a problem for sure!!

reseach the model for know failures..?

find anything yet??
 
this chassis was giving me a shorted vertical transistor when tested right after I had it running, when the chassis cooled down it tested normal. have to check the batteries in my meter. when I pulled the transistor it tested fine. it was reading 100v arcoss all three legs when operating, swapped a new transistor and still gave me those readings.
 
Resistor? or caps? connections?

http://www.arcade-museum.com/manuals-monitors/Atari Monitor TM-210 1st Printing Disco 19in.pdf


Based on the voltages you mention of 100vs
on all 3 pins means the transistor is not turned on..

Pg 13 schematic

R411 6.8 ohm would be a suspect in some case's

Pg 20 pictoral of parts and there location and transistor basing..
or pin configuration....


Q402 is 2sd478? is the part you were testing all pins had 100v's

Q403 is 2cs2073 Emitter is ground 0vs, Base ? collector ?

without the drive pulse from ic 401 the output q402 and q403 wont turn on.

from my experience both transistor should be replace as a pair

with new heat sink compound on the transistors.

Pg9 circuit description of vertical circuit

Check all vertical pots for

physical damage they are easy to break when using the wrong tool

to adjust bad connections to any of the pins on any pot could cause

loss of vertical deflection or vertical collapse vertical roll or open traces..

and it needs a cap kit if the electrolytics have never been replaced before.

Even bad connections on the fly could cause vertical issues because the supply

voltages come from it.
 
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