Vintage Bang & Olufsen Penta Restoration “Project Twins” – Part 4

This is the fourth part of the Bang & Olufsen Beolab Penta restoration. For the original post, see:

Vintage Bang & Olufsen Penta Restoration “Project Twins” – Part 1

Both amps were completely inoperable. Most of the capacitors were bad, all power transistors were blown, and various other parts needed replacing as well. I unfortunately didn’t take as many pictures of this process as the 100+ degree temperatures of the Texas summer and the lack of A/C in my workshop led me to neglect taking photographs.

Melted and cracked resistors:

More pictures of the burned resistors in the power stage:

Solder completely melted off from the molten-hot fried transistors:

Expanded and exploding large capacitors:

Fabricating a new fuse box:

Three rebuilt amplifiers! Where did the third one come from? I actually found another blown amp on eBay so I bought it and fixed it as well for a spare.

Rebuilding the control boards for the LED screen:

Next: Vintage Bang & Olufsen Penta Restoration “Project Twins” – Part 5

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  • delroy Jun 8, 2013, 7:14 pm

    hi there i hope you can help, i received 2 penta 3 speakers only, ones is fine but the other one speakers are fine but amp has loads of problems due to someone trying to fix .
    would you know how to fix or would you sell me one of your fixed ones if i sent you this broken one, i do repairs but this looks too messy for me to try its only one i need if not would you know were i could purchase one
    thanks delroy