No dash lights suddenly, just the small gauges, on the 77.

Slightly different issue than most of the posts about cluster lights.
All the lights worked last time I drove it at night. Been only day driving it for a couple months though.
Last night took a spin since I had the headlight on for a couple hours making light in the garage (power has been out for days).
Truck has 2 healthy batteries that both get charged so it started fine, however noticed that only the 4 small gauges had no light. Big gauges, gear selector radio heater etc all have light.
Haven’t had a cluster out of a squarebody in 30 years, so no memory here.
Are the 4 gauges powered by a single bulb and I may have just cooked that bulb, or is there another plausible diagnosis?
Thanks!

There's a few bulbs in that area. My hunch says there's a problem in the printed circuit since they all quit at once.

But it is possible that some bulbs quit or the bulb holders have dirty contacts and they failed one by one, but went unnoticed due to daytime driving.

Hey thanks. My guess is the circuit board then.
Now that I think about it I’ve only driven it a couple times since driving at night last and they all worked.
Doubt all of them on that side died basically at once.

There aren’t really that many bulbs in the cluster. Maybe 5 white dash lights, and the rest are turn signals and high beam indicator.

IIRC, on that left side there is one bulb near the top, between the two upper gauges. There is a 2nd bulb near the bottom, just to the right of the clock. You can probably reach your hand up and turn the black plastic retainer around the lower bulb to remove it. The upper bulb is probably too hard to reach with the cluster installed.