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-   -   Mitsubishi 90s VCR power off after a few seconds? (https://www.digitalfaq.com/forum/vcr-repair/13136-mitsubishi-90s-vcr.html)

WildcatMatt92 12-06-2022 01:23 PM

Mitsubishi 90s VCR power off after a few seconds?
 
I'm back to messing around with the Mitsubishi VCRs I have. At the moment I'm focusing on my mid-90s units, of which I have three: One HS-U550 (bought new, otherwise I wouldn't bother), one HS-U770 which I've had for about 8 years, and one HS-U770 which I bought off cheap off eBay as a parts machine.

All three of them have the same symptom. The unit will power up but after about 10 seconds they will automatically power off. It almost seems like it's doing some kind of startup check which is failing, and since all three behave the same way I suspect it's a common problem.

I suppose the place to start is to make sure all the outputs from the power supply are good (especially given how bad their early '90s power supplies are) but I wanted to ask if anyone else had run into this and had any suggestions.

(And before any wag wants to say "just go get a JVC", I have an HR-S7600U. I have a large box of tapes recorded on a very out of alignment machine which only these Mitsubishis seem willing to track.)

MrPete 12-06-2022 03:49 PM

I've been bringing an HS-U60 back to life. Same initial symptom.
MOST likely: belts that turned into mush! You can see one on the right side just opening the cover. Getting to the bigger one requires removing the mechanism.Other likely issues (mine had all of these):
  • needs cleaning of heads
  • needs retiming due to a gear slipping at some point
  • needs regreasing (old grease dried out)
12voltvids has several mitsubishi repair videos on youtube.

One I found that wasn't easy to search for: aligning the timing gears. https://www.youtube.com/watch?v=qiu5ON1m7i4

Hope that helps!

timtape 12-06-2022 06:22 PM

Quote:

Originally Posted by WildcatMatt92 (Post 88043)

(And before any wag wants to say "just go get a JVC", I have an HR-S7600U. I have a large box of tapes recorded on a very out of alignment machine which only these Mitsubishis seem willing to track.)

I'm curious as to why these Mitsubishi's track these very out of alignment tapes when others apparently dont. Can anyone think of an obvious reason?

lordsmurf 12-06-2022 06:53 PM

It may be as simple as the Mitsubishi also have misalignment to closer match the tape misalignment. But heads also didn't wear much, and the tracking zone is much wider.

The Mitsubishi D-VHS decks have pretty lousy tracking, terrible audio head alignment. It seems very few Mitsu decks survived, compared to JVC.

WildcatMatt92 12-06-2022 09:34 PM

Quote:

Originally Posted by MrPete (Post 88044)
I've been bringing an HS-U60 back to life. Same initial symptom.
MOST likely: belts that turned into mush!

Huh. Interesting that. And yeah, the belts have turned to goo so replacing them is worth a shot.

I see someone on eBay is selling belt kits but I don't really like the price and I'd rather get the actual belt sizes so I can get more when I need them...

Looks like the belt cross-reference is likely a PRB SCA3.0 for the loading motor but I can't find a PRB entry for the mid-90s stuff. The early-90s stuff seems to use SCB9.5. Did you come up with something similar?

Guess it's time for a piece of string and a yardstick.

Thanks for the tip!

MrPete 12-07-2022 06:02 PM

My apologies, I intended to mention this!I found a more reasonable source in Canada... waiting for the parts to show up ;)(At least for those in the USA, the money conversion is in our favor. My total including shipping is under US$15)


see here: https://kpcomponents.co/products/mit...elt-kit-vbk168

I should know in a day or two whether they are any good.

This after I tried some other "belt kits"... that claimed to have a square 2mm profile, but in reality were ultra-thin rubber bands. Useless.

MrPete 12-11-2022 02:44 PM

I received the belt kit. Sadly, it does not fit mine. Good news: I found more detailed data and a possible source! I'm also checking to see if I can obtain a refund on these belts, and whether the vendor has access to the correct ones.

1) A nice belt length calculator is at https://sudenga.com/resources/figuri...tween-pulleys/
2) See below for my calculations for my VCR -- Mitsubishi HS-U560
3) While my exact VCR belts are not listed ANYwhere, another web site provides exact specs on belts for a huge number of VCR's, and my own VCR specs are very close to two of the belts they list. See https://www.smcelectronics.com/vcrbltsq.htm Yours might also be similar :)



Measurement of Mitsubishi HS-U560 belt specs
Long Belt 114mm / 25mm / 13mm (Center-Center dist, diam, diam) ->
311mm belt w/o stretch (inside circumference)
Ideal would be 10% shorter so 280mm or 11.0 inches, maybe a little less
ideal would be 10%? 140mm // 14cm 5.5in half

Short Belt 26mm / 13mm / 7mm -> 84mm belt, 90% = 76mm or 3.0 in


Similar Belt Specs online at SMC (see link above)


Short belt: 3.0 in IC (inside circ), 0.077 in thick
(Replaces PRB SCA3.0, Pfantone 55607, EVG 1407-438, Sony 3-735-709-01)
Used on many brand/model VCR's, including Mitsubishi HS-250/HS-U28/HS-U38/
HS-U48/HS-U58/HS-U100/HS-U110/HS-U200/HS-U250/HS-U410.[FONT=Times New Roman]AND mine, HS-U560[/FONT]
[FONT=Times New Roman]
[/FONT]
Long belt: IC = 10.688", THK = 0.079".
(Replaces PRB SCA10.5, Pfantone 55681, EVG 1407-443,
RCA/Thomson 166796/167796, Sony 3-541-169/3-659-471-00/3-662-347-00)

Used in many VCR's and cassette players, incl Mitsubishi HS-U28/HS-U38/
HS-U48/HS-U58... AND mine, HS-U560.

MrPete 12-12-2022 11:12 AM

Wow. Looks like good sources, if you know what you want...

eBay
Marvac_2001 has many belts including what I need. Add all belts to ebay cart and pay ~only one base shipping charge. Just ordered, US$14.11 including shipping and my state sales tax.


Traditional
https://www.elliottelectronicsupply....ive-belts.html -- just buy the belts you want. Lower per-belt cost. $7.94 1st class pkg base shipping for me.
https://www.smcelectronics.com/vcrbltsq.htm -- same. Gives many VCR compatibilities, but fewer options. Higher prices, $4.95 base shipping.

Both appear to cost me around US$16.50 for the two belts. Waiting on a reply from KP Components


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