Can you use the simple past?
Answer: Using the simple past to state a simple fact is perfectly fine. However, what you are running afoul of is Tense Consistency. You can have multiple tenses in a single paragraph (or clause), but the time frames of those tenses should agree with each other.
Yesterday, when I was using a printer, it suddenly turned off in the middle of printing.
Here you're using the past progressive to describe an ongoing activity that was interrupted in the past. Perfectly fine.
I was surprised and pushed the power button many times, but it never turned on again.
You shift to simple past to make some statements of fact. Also fine.
I realized that it had broken down.
Now you shift into the past perfect to show that the printer, which had been working up until then, had now stopped. As the use of the printer and the event that ended its useful life both occurred in the past, using past perfect tense is perfectly fine here.
I used it for about four years.
Here's where things break down. Like the sentence before it, your use of the printer both started in the past, and ended in the past. As such, its tense should agree with the sentence before it, and thus be written as past perfect.