A payless payday looms this week for the Detroit Symphony Orchestra, whose officials say they will be unable to pay regular biweekly salaries to 155 employees because of worsening financial problems. Symphony Chairman Robert S. Miller says there is “no way” the orchestra will be able to come up with the $200,000 needed to give 97 musicians and 58 other staff members their full checks Thursday. The Detroit Federation of Musicians, which represents the symphony members, agreed to continue performing if the symphony could issue one-week paychecks. Miller said last month that the symphony would close in mid-July unless the state, city and businesses pledged $18.2 million for the next four years to help it overcome chronic financial problems. Since then, state, city and corporate leaders have given hopeful signs of additional funding but no hard commitments. The symphony has an $8-million debt that officials have said will reach $16 million by 1993.