Maybe You Have A Juicy Question?

[RealMarkDeneen]

12 minutes ago, tigerwoodKhorns said:

Mark,

 

If there are any other common failures can you post them?  Parts and solder are cheap and I think that many might want to just go ahead and do the replacements proactively if they are handy.

 

I have a Tercel 1 and if there anything that I should beef up I'd rather do it now. 

 

Thanks. 

 

There were really FOUR consistent failures.

1) The above mentioned Bridge Rectifier in either the BBX or Peach

2) The loosening up of the LM350 regulator on BBX and Peach. This is what would happen: The normal heat in the unit would soften the four NYLON standoffs that I used to hold the LM350 and it's 2" x 2" Heatsink to the PCB. They nylon would shrink down, the screws would loosen slightly, and the voltage would drop from 6.3 to 5, then 4 then the unit would stop working. One simple fix was to retighten the four screws. The better fix was to remove the nylon spacers and replace with aluminum and retighten.

3) The remotes in either of the ones that had remotes. The remote failure was simply this: The receptor sat behind a simple hole in the front panel, and it would get tweaked away from lining up with the hole.

4) The RCA jacks on BBX and Peach would get tweaked off the PCB. In many ways, this was the more regretful part of what I did. I wanted to hold the cost of the unit to well under $2 grand. And wiring 20 panel jacks was going to add a lot of labor. I saw these PCB mount jacks and an opportunity to save hours of labor and I designed it so there was no "wire" and used relays and a PC mount selector. It was all VERY LABOR SAVING, but just too fragile for reality. Big mistake. Now, those jacks are unobtainable. The solution is to drill 20 holes in the back panel, mount panale mount jacks, wire them into the PCB holes. Takes an afternoon to do it, but makes the unit bulletproof.

 

I can't recall any repairs on Merins, and maybe a few minor ones on Tercel. Nothing "chronic" on either of those. The second version of Tercel was REALLY ROBUST. I don't think I ever saw one back for repair.

 

pCAT had a few troubles, but not too bad. The welding on the chassis covers was shite. The fabricator did a crap welding job and the covers came apart in shipping. And on maybe two units a 2W resistor in the PSU burnt out. And the big star ground with big copper wires came loose from it's BOLT that kept it tied to the chassis on one unit. The biggest problem was shipping those things. Nearly impossible.

 

Cheers!

Mark

[RealMarkDeneen]

I know a lot of this sounds dreadful with all the problems. BUT.......if one can do the mods and repairs (or have them done), they will run for a long time trouble free. There were some design mistakes, but nothing that can't be resolved.

[tigerwoodKhorns]

29 minutes ago, RealMarkDeneen said:

I know a lot of this sounds dreadful with all the problems. BUT.......if one can do the mods and repairs (or have them done), they will run for a long time trouble free. There were some design mistakes, but nothing that can't be resolved.

 

It actually sounds pretty simple.  If someone can build a nice neat crossover they should have no trouble with this. 

 

FWIW I have some really nice receivers and DVD players that have the same issue with the RCAs.  

 

Thanks Mark. 

 

[Rex Everything]

A quick follow up. I tightened down the nuts on the LM350 per Mark's post above and the unit came on...

[RealMarkDeneen]

1 hour ago, Rex Everything said:

A quick follow up. I tightened down the nuts on the LM350 per Mark's post above and the unit came on...

 

Fantastic!

[tigerwoodKhorns]

1 hour ago, Rex Everything said:

A quick follow up. I tightened down the nuts on the LM350 per Mark's post above and the unit came on...

Please post a pic of the LM350. 

 

Mark, do you say to use aluminum standoffs for heat dissipation or more likely just to stand the heat. 

[Rex Everything]

7 minutes ago, RealMarkDeneen said:

 

Fantastic!

I did email you!

 

[RealMarkDeneen]

Just now, tigerwoodKhorns said:

Please post a pic of the LM350. 

 

Mark, do you say to use aluminum standoffs for heat dissipation or more likely just to stand the heat. 

 

Not for dissipation. It's just that the aluminum won't shrink when the insides of the unit get warm. The nylon literally shrunk by about 1//10".

NOTE: If you plan to replace the nylon for aluminum, you have to desolder the LM 350 and then resolder it. No biggie.

[RealMarkDeneen]

2 minutes ago, Rex Everything said:

I did email you!

 

 

Got it. I'll send some details to you in the morning.

Mark

[Rex Everything]

LM350 pics as requested...

[Rex Everything]

6 minutes ago, RealMarkDeneen said:

 

Got it. I'll send some details to you in the morning.

Mark

Thank you!

[Rex Everything]

Has anyone done a plate across the back for the rca ins/outs? That way only two holes need to be drilled in the chassis...? I'd like something like this that looks like it's stock.

Edited February 24, 2023 by Rex Everything

[tigerwoodKhorns]

18 minutes ago, Rex Everything said:

Has anyone done a plate across the back for the rca ins/outs? That way only two holes need to be drilled in the chassis...? I'd like something like this that looks like it's stock.

I would think that venting is an issue.  I have a Fisher and want to add 5 way binding posts and have been thinking about this.  It seems like you can add a plate with brackets and maybe mesh around it for a factory look. 

[capo72]

12 hours ago, Rex Everything said:

Has anyone done a plate across the back for the rca ins/outs? That way only two holes need to be drilled in the chassis...? I'd like something like this that looks like it's stock.

I did exactly what you describe on my BBX. Several years ago I had issues with the RCA jacks on the board a couple of different times. Mark was no longer working at the time so I decided to tackle the problem on my own; my solution was as you describe. I made a plate to go across the back to hold RCA jacks, then wired to the board as Mark describes. It caused me some other issues, but overall was a good solution. I can try to find pictures of the work I did, or take new ones. I actually made up 2 plates and only used 1 so I have an extra if someone is interested in doing this mod. 

[the real Duke Spinner]

20 hours ago, RealMarkDeneen said:

I know a lot of this sounds dreadful with all the problems. BUT.......if one can do the mods and repairs (or have them done), they will run for a long time trouble free. There were some design mistakes, but nothing that can't be resolved.

Just typical production problems. My Father had a very small R&D firm

Everything was one off production.  

There were things learned there about Mil- Spec that were invaluable

 

 

 

[RealMarkDeneen]

RCA JACKS

 

I have done at least 3 or 4 units in the past with panel mount jacks. I did NOT need to add an extra plate. There is sufficient room on the rear of the chassis above the opening where the rca jack protrude from the PCB.

 

If you cut the upper part of the vinyl label off, there is just the right amount of space. (If memory serves). I know I never added any plate when I've done this in the past. If you do add a plate you will be eliminating some of the cooling.

 

 

[RealMarkDeneen]

REPLACEMENT BRIDGE RECTIFIER

 

DIGIKEY 641-1381-ND About $5.

 

This should be done for all BBX and Peach models.

 

Easy fix.

Mark

[Travis In Austin]

4 hours ago, RealMarkDeneen said:

REPLACEMENT BRIDGE RECTIFIER

 

DIGIKEY 641-1381-ND About $5.

 

This should be done for all BBX and Peach models.

 

Easy fix.

Mark

As in do it now even if you have never had an issue?

 

 

[RealMarkDeneen]

21 minutes ago, Travis In Austin said:

As in do it now even if you have never had an issue?

 

 

Yes, that's my recommendation. I think they will all fail with time. Especially if it sits on for 8 hours at a time.

I have had enough failures to believe they will all fail.

Cheers!

Mark

[J M O N]

On 2/22/2023 at 9:14 AM, RealMarkDeneen said:

Glad to know they are working for you!

Yes they are -- still sounding great!  Thanks for the info!