PDA

View Full Version : My 5151 Monitor seems to have died.



fjk61011
July 14th, 2017, 06:43 AM
My 5151 Monitor seems to have died. I get a background of green with diagonal lines upward sloping left to right. They are about an inch apart.

Any ideas?

retrogear
July 14th, 2017, 09:29 AM
Does turning the brightness down have any effect? I assume not. Do you have a multimeter? The first step I would take is open it up and measure the voltages on the CRT pins 2 and 5.
The service manual is online. Pin 2 should be +50VDC and pin 5 -50VDC.

Larry G

glitch
July 14th, 2017, 09:45 AM
The VHOLD gets out of whack on mine every now and then, which usually results in me thinking it's broken until the underscore from the 5150's "testing RAM but telling you nothing" slowly rolls up from the bottom of the screen. Something to check!

fjk61011
July 14th, 2017, 11:23 AM
Does turning the brightness down have any effect? I assume not. Do you have a multimeter? The first step I would take is open it up and measure the voltages on the CRT pins 2 and 5.
The service manual is online. Pin 2 should be +50VDC and pin 5 -50VDC.

Larry G

Have a multimeter. I'll test tomorrow.

fjk61011
July 15th, 2017, 03:25 AM
switched on today. just a blank screen.

retrogear
July 15th, 2017, 02:23 PM
The horizontal drive comes from the PC. Screen will be black w/o it.

modem7
July 15th, 2017, 02:48 PM
switched on today. just a blank screen.
Although that symptom has many possible causes, one is that there is no horizontal sync signal coming into the 5151 (per what retrogear wrote).
So, consider:
- Poorly connected video cable (including oxidation on pins, etc.)
- 51xx motherboard's video switches set to EGA
- Faulty MDA video card