Fun with BPC: Mitsubishi CS-13RX1

[jedo1507r]

I picked up a 1992 Mitsubishi CS-13RX1 a couple of days ago out of the trash and coincidentally I needed a small set to take with me to the dorm in a couple of weeks to play news babble in the background and if the set gets trashed, I won't be too upset about it. Heck, I'll probably pass it on to someone else who wants to have news babble as their background noise.

The issue with the 13RX1 is that it fails to power up, though a relay clicks upon pressing the power button. As usual, I'm suspecting bad caps, so I'll do some troubleshooting later.





This "racetrack" style speaker is PATHETIC. Even cheap clock radios move more air than this. Also, I need to work on proper autofocusing.


Shot of the chassis and CRT board.

By the way: When did Mitsubishi's small sets become rebadged Sharp sets? At least the speakers gained in size.

[Endspec]

I have had my puter monitors do this, I found bad solder joints around the flyback tranny and the hi voltage power supply, turn the board over and look close and resolder that area and see if it helps.

[dr.ido]

Check the horizontal output transistor first. Generally speaking I find a lot of these small sets eat them, but the flybacks are usually okay. Otherwise, it's probably a power supply fault. Other than the usual obvious faults the relays themselves do fail. Usually you can pop them open and clean the contacts.

[radiotvnut]

If the horizontal output transistor shorted, it probably took out a B+ fuse or fusible resistor in the power supply and maybe the voltage regulator IC. Also, Mitsubishis of this age are prone to leaking electrolytic caps. I finally got to the point where I wouldn't work on a Mitsubishi because I got tired of replacing 50 caps and cleaning up the mess they made. The ones from the '70's and early '80's were OK. They went downhill after that.

[jedo1507r]

Endspec: it works! Various cold joints in the HV section.

dr. ido: I was cringing when I thought of that.

Radiotvnut: I had to do that to my parents' 2003 Mitsubishi WS-55311 RPTV recently. The set's status LED blinked and refused to power up. Those caps suck. I mean those really SUCK. I like the blue tubed Mitsus of the '80s and I do see a few of those around town.

Thanks everyone!


Surprisingly the CRT is strong, the set really did not have many hours, but it was moved around quite a bit. I have grown to dislike the early menu-driven sets because of the wonky interface.

[MRX37]

Originally Posted by jedo1507r

I like the blue tubed Mitsus of the '80s and I do see a few of those around town.

I have one of these. Made in 1984.

[jedo1507r]

Originally Posted by MRX37

I have one of these. Made in 1984.

Yep, I saw an 19-inch entry-level '84 Mitsu at a local SA recently and a 25-incher (I think around 1985-ish) with a trick sliding control panel at another thrift. Very distinctive looking tube.

[zenith2134]

Once found a 1987 13" MGA color set that had the purplish phosphored tube face. Great picture; used it in the kitchen for a while then gave it away.

Nice fix.

[zenithfan1]

Originally Posted by zenith2134

Once found a 1987 13" MGA color set that had the purplish phosphored tube face. Great picture; used it in the kitchen for a while then gave it away.

Nice fix.

We all know where one of those is, sadly, the I 94 project it moving the frontage road right through the house.

[wa2ise]

I had a rectifier diode on the secondary of the switching supply circuit go shorted in a BPC set. Took a while to find it. Used a replacement from a dead PC monitor power supply, the replacement did similar duty in the monitor. Now it works. I'm a little unhappy in that I couldn't identify any reason why the original diode died.